Electrical plug and socket



April 16, 1946. 6:. A. GEERS ET AL 5 5 ELECTRICAL PLUG AND SZJCKET I Filed July 14, 1943 INVENTOR. C d

Patented Apr. 16, 1946 3 This invention relates to' electrical plugs'and sockets for thesconveyance of electrical'current from the busor vpower lines to lelectrical utilities to be operated thereby, and-the general object of the invention is toprovide a relatively simplified:

method and means for making suchconnections.

"A further object of the invention is to provide an electrical plug comprising a base or body portion. defined by four side .Walls, of which two of the opposite walls thereof are convexed in formation on a longitudinal section, and the remaining .twoopposite Walls are concaved on a similar longitudinal section; the surfaces of the four walls merging laterally and gradiently into one another and also tapering inwardly from the outer end of the plug towards the inner end thereof, in such manner that any crosssection of the base of the plug inwardly of the flat. and narrow extremity thereof would be oval, ovate or elliptical in outline, the ovateness of the sections increasing from thewouterlend towards the inner endlof the plug, the: said plug having an elongated and regularly formed'flat stem, prongor tongue axially extended'frornits innerend, and a receptacle havinga socket formed therein nicely complemental to the described p'lugeand thus adapted to freely. and

snugly receive and seat the plug, there being elec-.

trical conductors extended throughv the plug and alongnthe opposite edges of the said flat' stem thereof,-.-with the inner ends of the said conductors. arranged. and adapted for" slidably contacting electricalterminals seated withinthe inner endof-V the socket of the receptacle, the said terminals. being in turn conventionally connected with the 'mainbusor power. lines of the installa-- tion. 1

- A further object is to provide an electrical plug defined On its sides by concavo-convexwallstaper'ed inwardly to forma base;that, isovate in cross section, and a receptacle formed with a socketrcomplementa'1 to, the plug, toreceive and seat the latter, whereby electrical vconnections-are more, easily made than with the usualtwopronged plugs, even in darkness or where the receptacle may be located in a ratherinaccessible or difiicult position, the complemental formations i lu an socket be n su h as .w l adth rl e readily and almost automatically into the socket,

tocornplete theelectrical connection, A further object of the ,inventionis to provide an electrical receptacle formed'witha sockethavingtwo opposite-sides or wallsconvexed from end men Qft e socke and th remain n two os te. i iesrcr-. a s c n a ed om endlt end oi the, socket, the. sur aces pf these W lls m r in Application July-14, 1943, Serial Nuisances :1 i

" l Claiirnjj (cil a-432) laterally and gradually into one another and-bee ing also tapered lnwardlyirom theouterto'the inner end of the soc'liet, so that various crossfsections as taken" through the socket would be increasinglyoval or ovate in'form fromthe *outer to the inner end or the socket; the said socket terminating in a regularly" elongated and flat channel or duct opening out through theinner end ofthe -receptacle,*therebeing electrical terminals-or contacts seated within the opposite con striated margins of the channel arranged for connection with the DQWeror bus lines ofth in"- stallation; and an electrical plug formed complementally to the socket of the receptacle and thereby adapted to'nicely andfreelyslideinto and seat itself within the socket of the receptacle, the plug being formed with a flat stem or pron adaptedto slidably pass within the flatchannel of the'socket oi the receptacle,-there being conductors extended throughthe plug and. along the edges of the fiat stem thereof adaptedtoslidably Contact the said terminals of the flat oh'annel at the inner; end of the socket of the receptacle.

A further object is to provide an electricaljre ceptacle formed with afsocket having ai's'ingle opening at the inn er end thereof, the s'aid .opening being oval'or oblongin cross 'sectiohjand an electrical" plug iormed 'complen'ientally to seat within the socket of the receptacle "andhaving a single prong extended at its inner end, said prong being ovate or oval in cross section, to slide into the complemental opening at the inner end of the socketof. the receptacle, and conductors and terminalsmounted in the plug and in the socket of the receptacle 'for "completing an electrical connectionwhen the plug is seated in the receptacle.

With the foregoing objects in view, together with such other and further objects and advan-..

tages as may appear from the following specificatiOn attentiOn' is now directed to 'the accom panyingdrawing wherein are shown certain preferred I embodiments of" the invention, and wherein: f Q v f v a Figure 1 is a perspective view of asocketed receptacle and its associate coniplemental fplug, formed in accordance with this invention,=the lugbeing shown as partially withdrawn from the receptacle. v r i v j 1 1 Figure 2 is alongitudinal section throu h the plug and receptacle as represented in Figure l, 1 7

t Figure 3 is a side elevation of the plug as represented; in Figure l, taken at an angle o fninety e ees rom, the iew o F re d she its an deewi e view c -the us-s em l Figure 4 is a top plan view of the assembled plug and receptacle.

Figure 5 is a bottom plan view of the assembled plug and receptacle. v

Fig. 6 is a sectional view of the body of the receptacle shown in Fig. 2.

Fig. 7 is a section of the body of the receptacle taken at an angle of ninety degrees from the view of Fig. 6.

The invention-comprises an electrical plugrepresented generally at 5 and made of any suitable non-conductive or dielectric material, such as Bakelite, rubber or plastic. The plug 5 is here shown as formed with a circular head 6 which .is exteriorly threaded as indicated .at. 'l for enga ing the interiorly threaded margin off-the semispherical cap 9, as indicated at 8. Thecap 9 is apertured as at ID for passing electrical wires or conductors from the plug outwardly. Thus this cap may be readily secured on the plug,'0r it may be removed when necessary for inserting, replacing or repairing the wires.

For the sake of clarity and convenience, the capped end of the plug is hereinafter referred to as the outer end thereof, and the opposite end is referred to as the'inner end thereof.

Inwardly of the circular head 6 the baseor body portion H .of the plug is formed with and defined by four sides or walls, including two oppositely disposed and inwardly inclined and tapered concaved walls l2, designated as side walls, and two oppositely disposed and inwardly inclined and tapered, convexed end walls I3. The walls .12 and I3 gradiently merge into one another at their margins, and they also taperingl-y meet inwardly at .a common point l4. Thus all cross sections as taken through the base or body portion H of the plug. will be defined by :oval, ovate or ellipticalmargins, with the characteristic of ellipticity regularly increasing .from the outer end of the plug to the inwardly located point 14, the common meeting point of the inner ends of the walls 12 and I3. From the point I4 the plug is axially and regularly extended in the form of a relatively thin, flat and narrow contact stem, prong or tongue 15, which is also oblong or elliptical in cross section; and the plane of which coincideswith the medial plane cutting .through the convexed end walls I3, as clearly shown in the drawing.

A pair of short wires or strip metal conductors are extended through the base and head of the plug in a spaced relation, through bores formed therethrough for the purpose. These conductors are indicated at l6, and they emerge at the inner end of the plug immediately at 'the'latera'l edges of the contact stem l5, to which edges theymay be secured in any conventional manner. These extended ends of the conductors-l6 are indicated at 16b, and they serve as contact terminals in manner 'later to be pointed out. The outer ends of the conductors l6 are turned angularly out and flattened upon the head of the plug, as indicated atlBa, and are tapped through to receive small screws l1, whereby outer service wires l8 may be operatively secured to the ends l6a of the conductors l6, after passing through the aperture ID of the cap 9. The screws I 1 also pass .into the head of the plug, for firmly anchoring the wires or conductors thereto. Thus the plug is completed.

A receptacle for the described plug is provided, the same being represented generally at 2B- and including a bodyportion 2! of dielectric material adapted for seating in a base-board "22 or in any other desirable location. For this attachment the outer end of the body portion is formed with an encircling flange 2la. through which screws 23 may be passed into the base-board.

The receptacle 20 is formed with a socket 24 which is substantially complemental to the shape and configuration of the base or body portion of the plug 5. Hence this sockethas two oppositely disposed and convexed side walls 25 which are inwardly inclined and tapered towards the inner end of the socket, and two oppositel disposed and .concaved end walls 26 which are likewise inwardly inclined and tapered towards the inner end of the socket, whereby the socket is adapted to freely and snugly receive and seat the base or body portion H of the plug. It is to be noted that th walls of the socket 24 also gradiently merge at their margins, as do the walls of the plug, thus ensuring the exact inter-fitting of the plug and socket. At itsinner end the socket 24 is extended in the form of a straight, narrowand .fiat duct -or channel 2.1, the plane of which is disposed in the plane cutting medially through the concaved end walls 26 .of the socket. Thus this duct 2-1 extends axially from the .inner end of the main socket, from the point 28 thereof which marks the meeting point of the inner ends of the walls of the socket, to a length approximately equal to the length of the stem .or prong 15 of the plug 5. The duct :21 is dimensioned to :freely receive the stem .15 of the plug, but the duct :is slightly widened relative to thisstem, as indicated at 21a, thus providing elongated .recesses which are over-hung and protected by .the overlying margins 26a of the inner ends of the end walls 126 of the socket 24. Within these elongated recesses 2.1a a pair of looped terminal conductor or contacts 29 are mounted and secured in place in anyconventional manner, as :by passing small screws "3'! through the angularly out-turned ends "2911 of one .leg of each of these looped terminals. It is to be noted that the term'inals 29 :are formed of spring wire or spring metal strips which .are doubled .medially upon themselves, and that they are disposed within the recesses 21:: with the bightsof the loops located upwardly immediately within or under the overhanging margins 26a of the end walls 26 of the socket j2ll. Thus these "terminals arenot only protected from .dislodgement :in the operation of inserting the plug, but because of the narrowness of thechannel or duct '21 it is impossible for children to insert their fingers into this channel or into contact with the terminals or contacts '29. Conductor wires 30 runningfrom the power or bus lines (not shown) are connected to the screws 3| of the terminals 2.9, for completing the installation.

In use and operation and owing to thedescri'bed unique construction of the plug and socketed receptacle, the former is readily and almost automatically seated within the latter without any trouble or difficulty, even in the dark. In this operation the single prong or stem of the plug is easily led into the single ductor channel at the inner-end of the socket of the receptacle, and the ovate and concave or concave-convex formations of the walls of the plug and of the socket, cooperate through the ellipticity of the resulting cross-sectional structures, to automatically lead the plug to its seat in' the socket, so that the terminal contacts 16b may be readily inserted in the duct or channel 2-! of the socket 2'4, and into slidable engagement with the-terminals 29 'located in the margins of this channel, thus completing the electrical connection. The resilience of the looped terminals 29 ensure at all times a positive contact thereof with the terminals or contacts I612.

The head 5 of the plug 5 is here shown as circular, for the purpose of threading it to enwell as the head itself, might also be of oblong or elliptical formation conformably with the base of the plug, and any conventional mean might then be employed for covering or protecting the lead out wires at their juncture with the conductors passed through the plug.

We claim:

In a device of the kind described, an electrical receptacle having a socket formed therein elliptical in cross section, with the side and end walls thereof taperingly converging from the outer end of the socket towards the inner end thereof, the gage the threaded cap 9. Otherwise this cap as socket being increasingly elliptical in successive cross sections from its outer end towardsits inner end, the inner extremity of the socket being formed regularly as a straight, flat and relatively narrow duct extended axially from the main 7 socket, electrical terminals mounted in the con- While we have here shown and described cer-- it gether with certain specific structural features thereof, it is understood that minor changes and.

modifications may be made in the structural features as here shown, not departing however from the coverage or limits of the appended claim.

stricted margins of the said duct, whereby the said receptacle as so formed is adapted to removably receive a, complementally formed electrical plug. CYRUS A. GEERS. FERGUSON B. GEERS. WILLIAM A. GEERS. 

